Need to pay attention to the problem of welding stainless steel lap joint stub end
General stainless steel lap joint stub end has certain corrosion resistance, heat resistance and wear resistance, commonly used in power plants, chemical, oil and other equipment and materials. Stainless steel elbow welding is poor, should pay attention to welding process, the premise of heat treatment and selection of appropriate electrode. In order to improve the corrosion resistance and the welding of the appropriate increase in the amount of non random elements Ti, Nb, Mo, welding is better than the stainless steel elbow. When using the same type of chromium stainless steel welding rod, should be more than 200 degrees above the preheating and welding of 800 degrees after the tempering treatment. If the welding parts can not be heat treatment, the use of chromium nickel stainless steel welding rod.
The coating of stainless steel lap joint stub end of titanium calcium type and low hydrogen type. Titanium calcium type can be used for AC and DC, but the AC welding penetration depth is shallow, at the same time easily red, so as far as possible the use of DC power supply. The electrodes should be kept dry when using titanium calcium type by drying at 150 deg.c for 1 hours, low hydrogen by drying at 200-250 Deg. C for 1 hours (not repeated drying, or medicine skin easily cracking), prevent the covering of viscous oil and other dirt, lest cause the weld increase the carbon content and the influence of welding quality.
During welding, the carbide is repeatedly heated to reduce the corrosion resistance and mechanical properties. In order to prevent the eye caused erosion due to heating, welding current should not be too large, less than about 20% carbon steel electrode, the arc layer should not be too long, fast cooling, narrow welding bead. Stainless steel after welding flanging sclerosis is large, easily crack. If you use the same type of stainless steel welding flange, must be preheated 300 DEG and 700 DEG C after welding the slow cooling treatment. Finally, small make up to remind you, in dealing with welding must pay attention to the above mentioned points of attention, with half the effort, to provide users with the best products.
Source: Yaang Pipe Industry Co., Limited (www.yaang.com)